It is known to make tubular articles, specifically one-piece pantyhose on a circular knitting machine which includes means for forming, during knitting, a longitudinal slit destined to become the waist opening in the completed garment. See for example Johnson U.S. Pat. No. 3,673,821. It is also known to incorporate, during knitting of one-piece pantyhose, one or more elastic yarns adjacent the slit for the waist opening, destined to become an elasticized waist band in the completed garment. See for example U.S. Patent Application, Ser. No. 252,011, filed May 10, 1972 by Vincicio Luchi. Difficulty has been encountered in the known prior art in providing sufficient elasticity and in preventing the elastic from unravelling or pulling loose from the fabric of the pantyhose. The problem arises because it is necessary to cut the elastic yarn while the grment is being knit, and the cut ends of elastic tend to be pulled through the stitches of the fabric when the garment is subsequently subjected to the normal handling of pantyhose.
The slit for the waist opening generally extends longitudinally of the garment, or wale-wise as the garment is knit from toe to toe. This is necessary in order to make the opening large enough to be practical when the garment is made on a conventional circular hosiery knitting machine having a needle cylinder of about 4 inches in diameter. The slit is conventionally made during knitting by one of several known methods, including cutting successive stitches in a predetermined length of a selected wale with a specially constructed and actuated sinker. See U.S. Pat. No. 3,564,873. The manner in which the slit is made does not form a part of the present invention, and the invention is applicable to provide an elasticized welt or border for a slit formed in any desired manner during knitting of a tubular fabric on a circular knitting mchine.